By Cliff Corcoran

The only team in the American League East with a losing record entering Thursday's action is the Toronto Blue Jays. Toronto is 32-33 and has posted the second-best record in the American League since April 29, going 25-16 (.610) over that span. Given that, it's well within the realm of possibility that no team in the AL East will finish with a losing record this year. That has only happened twice in the first 48 years of divisional play (it was impossible before that, when each league was a zero-sum proposition). In 2005, their first year in Washington, the Nationals finished last in the National League East with an 81-81 record. Even more impressively, in 1991, not one of the seven teams in the American League West finished with a losing record. That year, the California Angels came in last at 81-81.

The aggregate winning percentages of those two divisions were .525, for the 2005 NL East, and .526 for the 1991 AL West. However, neither ranks among the top 20 divisions according to aggregate winning percentage. Entering Thursday's action, this year's AL East has an aggregate winning percentage of .535, but even that is outside of the top five. With an eye on the history that the AL East could make this year, here's a look at the best aggregate winning percentages in the history of divisional play.

1. 2002 AL West: .566
2. 2001 AL West: .565
3. 2012 AL West: .542

If we treat all divisions equally, the AL West, which included just four teams from 1994 to 2012, takes the top three spots. The 2001 AL West was a four-team division led by the 116-win Seattle Mariners, but it also included a 102-win A's team, the combination of which easily offset the Angels and Rangers, who lost just 87 and 89 games, respectively, but still managed to finish 41 and 43 games out of first place. The next year, despite losing Jason Giambi, Johnny Damon and closer Jason Isringhausen to free agency, the Moneyball A's won 103 games and the division, the Angels leapfrogged the Mariners to win 99 games and claim the Wild Card on their way to their first, and still only, World Series championship, and the Mariners hung tight with 93 wins, leaving only the Rangers languishing 21 games out of third place with 90 losses.

As for 2012, that was the year the A's came out of nowhere to slip past the defending division champion Rangers on the final day of the season by completing a three-game sweep of Texas in Oakland. As a result, they would win 94 games and the division to the Rangers' 93 and the Wild Card. The third-place Angels won 89 games. The last place Mariners only lost 87.

If we limit our list to divisions with five or more teams in non-strike years, however, we find that the top eight spots belong to the American League East, the dominance of which dates all the way back to the first season of divisional play in 1969 and is spread fairly evenly over the intervening decades.

1. 1998 AL East: .53827
2. 1983 AL East: .53826
3. 2008 AL East: .5377
4. 2013 AL East: .5339
5. 1980 AL East: .5327
6. 2010 AL East: .5321
7. 1979 AL East: .5302
8. 1969 AL East: .5299

The 1969 AL East benefitted from both of that year's expansion teams, the Kansas City Royals and Seattle Pilots, being placed in the NL West, but it also had a truly great team in the 109-win Orioles, and the only expansion Washington Senators team ever to post a winning record (going 86-76 in Ted Williams' first season as manager). The only team to lose more than 81 games in that six-team division was the 99-loss Indians, though the fifth-place Yankees left a game unplayed and finished 80-81.

The 1979, '80 and '83 AL Easts, all seven-team divisions, are representatives of a period during which the American League was dramatically lopsided. In a ten-year span from 1975 to 1984, the only AL West team to win the pennant was the 1980 Royals, who upset a 103-win Yankee team to do so. That year, the Orioles won 100 games and finished in second place, while the 86-win Brewers and 84-win Tigers were coalescing into the teams that would win the '82 and '84 pennants. The '79 AL East was arguably even better, with the Orioles winning 102 games, Milwaukee 95, Boston 91, the Yankees 89 -- failing to win the division for the only time during a six-year span from 1976 to 1981 in the season that brought the death of their captain, Thurman Munson -- and the Tigers 85. Even sixth-place Cleveland had a winning record at 81-80. However, the expansion Blue Jays, who lost 109 games in their third year of existence, brought down the division's aggregate performance considerably. In 1983, the top five teams in the division -- Baltimore, Detroit, New York, Toronto (enjoying its first winning season), and Milwaukee --won 87 games or more. Each of those five teams would win the division from 1981 to 1985.

The 2008, '10 and '13 AL Easts represent a period of surprising parity for a division which finished in the same order -- Yankees, Red Sox, Blue Jays, Orioles, Rays -- six times from 1998 To 2003. In a six-year span from 2010 to 2015, all five teams won the division at least once. That parity actually began in '08, when the Rays dropped the "Devil" from their name and ascended from worst to first, winning 97 games to edge out the 95-win Red Sox, whom Tampa Bay would then beat in the playoffs to clinch their first, and still only, pennant. In Yankee Stadium's final season, New York missed the playoffs for the first time since before the 1994 strike, but still won 89 games, leaving the Blue Jays in fourth place despite their 86 wins. Flip the Yankees and Red Sox and the 2010 AL East was nearly identical, with the Rays on top with 96 wins, and the Blue Jays in fourth with 85. The Orioles joined the party in 2012 and finished tied for third with the Yankees in 2013 with 85 wins, behind the 97-win Red Sox, who went on to win their third championship of recent vintage, and the 92-win Rays. Meanwhile, the last-place Blue Jays lost just 88 games.

As for 1998, the 114-win Yankees did the heavy lifting that year, but the Red Sox contributed 92 wins, the Blue Jays 88, and the fourth-place Orioles only lost 83 games.

If this year's AL East finishes with the same aggregate winning percentage it carries into Thursday's action, it would rank fourth on the above list.

Here are the best showings by Baseball's other divisions:

NL East

1987: .529

Team

W

L

Pct.

GB

Cardinals

95

67

.586

-

Mets

92

70

.568

3.0

Expos

91

71

.562

4.0

Phillies

80

82

.494

  15.0

Pirates

80

82

  .494

15.0

Cubs

76

85

  .472

18.5


Whitey Herzog's Cardinals prevented a Mets repeat, while the top three teams in the division won 91 or more games and the last-place Cubs had a .472 winning percentage.

NL Central

2015: .527

Team

W

  L

  Pct.

  GB

Cardinals

100

  92 

  .617

-

Pirates

98

64

  .605

2.0

Cubs

97

65

  .599

3.0

Brewers

68

94

  .420

32.0

Reds

64

98

  .395

36.0


The Cubs' 97 wins in 2015 are the most ever by a third-place team in the Wild Card era, and the most by a third-place team in any alignment since 1977.

AL West

1991: .5264

Team

W

  L

Pct.

   GB

Twins

95

67

  .586

-

White Sox

87

75

  .537

8.0

Rangers

85

77

  .525

10.0

A's

84

78

  .519

11.0

Mariners

83

79

  .512

12.0

Royals

82

80

  .506

13.0

Angels

81

81

  .500

14.0


If we disregard the four-team AL Wests, the 1991 version takes the top spot in division history. Again, this was one of just two divisions not to include a single losing team, along with the 2005 NL East. How is that possible? Over in the AL East, which was the weaker of the two AL divisions in the late '80s and early '90s, the Yankees lost 91 games, the Orioles lost 95, and Cleveland lost 105. Remarkably, those three teams did the losing for the entire league, as they were the only teams with losing records in the 14-team American League that year.

NL West

2000: .5259

Team

W

  L

  Pct.

  GB

Giants

97

65

  .599

-

Dodgers

86

76

  .531

11.0

D-backs

85

77

  .525

12.0

Rockies

82

80

  .506

15.0

Padres

76

86

  .469

21.0


Despite the high aggregate winning percentage, there wasn't much drama here. The Dodgers were not only 11 games behind in the division but eight games behind the Mets for a Wild Card spot. This division was more about a lack of bad teams than an abundance of good ones.

AL Central

2006: .519

Team

W

     L

  Pct.

    GB

Twins

96

66

  .593

-

Tigers

95

67

  .586

1.0

White Sox

90

72

  .556

6.0

Indians

78

84

  .481

18.0

Royals

62

100

  .383

34.0


In 1994, its first year of existence for the AL Central, the division had a .5325 aggregate winning percentage and was topped not by Cleveland, which finished a game out of first place, but by a 67-46 White Sox team led by AL MVP Frank Thomas. Unfortunately, the strike cut that season short. In the 23 years since, including this one, the AL Central, historically MLB's weakest division, has had an aggregate winning percentage above .500 just five times, and three of those barely made it:

2006: .519
1996: .516
2015: .506
2014: .502
2008: .501

In 2006, the defending world champion White Sox won 90 games, but were relegated to third when the Twins, who woke up in third place on September 4, surged past Chicago and Detroit to win the division on the final day of the regular season. Despite that surge, it was the Wild Card Tigers, who lost the final five games of the regular season to hand the division to Minnesota, who won the pennant.

* * *
Cliff Corcoran is a Sports on Earth contributor and a regular guest analyst on the MLB Network. An editor or contributor to 13 books about baseball, including seven Baseball Prospectus annuals, he spent the last 10 seasons covering baseball for SI.com and has also written for USA Today and SB Nation, among others.